1. Field of the Invention
The invention relates to a hand tool having multiple bits or other tool elements selectable for use one at the time. The bits or tool elements are movable between a retracted storage position within the handle of the tool, and an extended operative position.
The hand tool is normally a screwdriver. However, while the words “screwdriver” and “bits” are used for convenience throughout this description, it should be understood that these words are intended to be interpreted liberally, and thus could include hand tools with such tool elements as pen/pencil or scribing tips, or other non-screwdriver bits.
The invention is particularly directed towards a mechanism for automatically locking the tool elements in their operative position, when extended to that position.
2. Description of the Prior Art
In the past, different approaches have been tried to provide a hand tool or screwdriver having a plurality of bits accessibly stored in the handle of the screwdriver. Examples include U.S. Pat. No. 3,750,729 (Lemieux), U.S. Pat. No. 5,325,745 (Koehler), Canadian patent no.2,353,911 (Beauchamp), and U.S. Pat. No. 6,332,384 (Cluthe). The latter reference is by the present inventor.
However, to date there have been no satisfactory means for automatically locking the bits in their operative position, once extended to that position.